4 Any late stage complication of diabetes (e.g. retinopathy, polyneuropathy, vegetative disorders, diabetic foot) 5 Renal insufficiency (calculated creatinine clearance < 80 ml/min/1.73m²) 6 Cardiac insufficiency NYHA II-IV, myocardial infarction, other known cardiovascular diseases including hypertension > 160/95mmHg (measured at training visit and each of the timepoints of Day -1), stroke and TIA 7 Neurological disorders (such as epilepsy) or psychiatric disorders 8 Acute or relevant chronic infections (e.g. HIV, repeated urogenital infections) 9 Any gastrointestinal, hepatic, respiratory, endocrine or immunological disorder 10. History of relevant allergy/hypersensitivity (including allergy to drug or its excipients) 11. A marked baseline prolongation of QT/QTc interval (e.g., ECG demonstration of a QTc interval >450 ms ) at screening visit